Like triads, four note chords can be played in various inversions. Because there are four notes, there are also four possible inversions - Root Position (root in bass), First inversion (3rd in bass), second inversion (5th in bass) and Third inversion (7th in bass). This can be demonstrated with a C7 chord which contains the notes C, E, G and Bb.
Closed (alphabetical order) voicings of four note chord inversions are not very practical on the guitar because they require large finger stretches. Because of this, open voicings are commonly used. The following diagrams demonstrate this with a first inversion C7 chord in closed position followed by an open voicing.
By using open voicings, it is possible to find comfortable fingerings for all inversions of four note chords along groups of strings. Here are some practical voicings for inversions of a C7 chord on the first four strings.